JP2020085204A - Sleeve and joint including the same - Google Patents

Abstract

To provide a sleeve that can further reduce its size in an axis direction of a joint while maintaining high sealability.SOLUTION: A sleeve is a cylindrical member for connecting a tube to a cylindrical body of a joint. The sleeve comprises a first peripheral wall end part facing a peripheral wall end part of the cylindrical body, and a second peripheral wall end part press-fitted into an opening end part of the tube. The first peripheral wall end has an annular projection that is press-fitted into an annular groove included in the peripheral wall end part of the cylindrical body, or the annular groove into which the annular projection included in the peripheral wall end part of the cylindrical body and axially projecting is press-fitted. The second peripheral wall end part has a bulging part for expanding the diameter of the opening end part of the tube from the inside. The outer peripheral part of the first peripheral wall end part has a flange axially facing the peripheral wall end part of the cylindrical body.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a joint or the like, and more particularly to a joint for connecting tubes by using a sleeve.

In a semiconductor process, various chemicals are used for coating a resist on a wafer, cleaning the wafer, and the like. Piping equipment such as tubes, joints, valves, and pumps that handle these chemicals are included in the semiconductor device manufacturing line. The features of this piping facility are that all the parts that come into direct contact with the chemical liquid are made of fluororesin, and that maintenance such as cleaning is relatively frequent. The former aims to prevent semiconductor crystal defects due to metal contamination and the deterioration of electrical characteristics, and the latter aims to prevent wiring processing defects due to fine particles and film formation abnormalities due to organic substances. Based on these characteristics, this piping facility is required to have high sealability and easy assembly and disassembly.

For example, the joint disclosed in Patent Document 1 uses a sleeve for connecting tubes. As a result, a high sealing property is maintained even if the product is once disassembled and then reconfigured. Like the joint body, the sleeve is made of fluororesin, and one end of the peripheral wall is press-fitted into the open end of the tube, and the other end of the peripheral wall forms a seal structure with the peripheral end of the joint body. In this seal structure, the peripheral wall end of the sleeve includes, for example, an annular protrusion. The annular projection projects in the axial direction of the sleeve and extends in the circumferential direction, and is press-fitted into a circumferential annular groove included in the peripheral wall end of the joint body. The peripheral wall end of the sleeve additionally includes a circumferential annular groove. The annular protrusion included in the peripheral wall end of the joint body is press-fitted into the annular groove. Since the annular projection has a slightly larger radial width than the annular groove, the annular projection is pressed into the annular groove by a press fit without any gap in the radial direction. As a result, high sealing performance is maintained. The sleeve is removed with the tube as it separates from the fitting. This makes it easier to disconnect and then reconnect the tubes than if the tubes were directly connected to the fitting body.

Japanese Patent No. 5883907

As the semiconductor process becomes multi-staged, piping equipment becomes complicated. Further miniaturization of piping equipment is required for the purpose of avoiding an excessive increase in the scale of a semiconductor manufacturing line. However, it is difficult to reduce the axial size of the sleeve in the existing joints, particularly in the type using the sleeve like the one disclosed in Patent Document 1. This is for the following reason. In these joints, the press-fit length of the sleeve with respect to the tube must be designed to be sufficiently large in order to prevent the tube from coming off the sleeve. Accordingly, the deflection of the tube tends to tilt the shaft of the sleeve from the axial direction of the joint body. If this inclination becomes excessive, the sealing force between the sleeve and the joint body will be impaired. For the purpose of avoiding this, the peripheral wall end portion of the joint main body includes a male screw (a cylindrical structure having a screw formed on the outer peripheral surface). The male screw projects in the axial direction from the entire circumference of the peripheral wall end portion of the joint body, and the projecting length thereof is sufficiently large. The male thread holds the tube and sleeve tightly on the inner surface, preventing tilting of the sleeve axis regardless of tube deflection. On the other hand, the length of the male screw prevents the size reduction of the joint in the axial direction.

An object of the present invention is to solve the above problems, and to provide a sleeve that enables further downsizing in the axial direction of the joint while maintaining particularly high sealing performance.

The sleeve in one aspect of the present invention is a cylindrical member for connecting a tube to the tubular body of the joint. The sleeve has a first peripheral wall end facing the peripheral wall end of the tubular body, and a second peripheral wall end press-fitted into the open end of the tube. The first peripheral wall end portion has an annular protrusion that is press-fitted into an annular groove that is included in the peripheral wall end portion of the tubular body, or an annular groove that is axially protruded in an annular protrusion that is included in the peripheral wall end portion of the tubular body. .. The second peripheral wall end has a bulge for expanding the diameter of the opening end of the tube from the inside. The outer peripheral portion of the first peripheral wall end portion has a flange that axially faces the peripheral wall end portion of the tubular body.

The flange may be axially spaced from the peripheral wall end of the tubular body, or may be in contact with the peripheral wall end of the tubular body. The contact portion of the flange with the end of the peripheral wall of the tubular body may include an inclined surface with respect to the axial direction.

A tube is connected to the joint according to one aspect of the present invention. This joint is composed of a tubular main body including a male screw extending in the axial direction at the end of the peripheral wall, a sleeve connecting the tube to the end of the peripheral wall of the tubular main body, and a tube inserted from one side to the inside and the other side. And a nut into which a male screw at the end of the peripheral wall of the tubular body is screwed inward. The sleeve includes a first peripheral wall end facing the peripheral wall end of the tubular body, and a second peripheral wall end press-fitted into the open end of the tube. The first peripheral wall end portion has an annular protrusion that is press-fitted into an annular groove that is included in the peripheral wall end portion of the tubular body, or an annular groove that is axially protruded in an annular protrusion that is included in the peripheral wall end portion of the tubular body. .. The second peripheral wall end has a bulge for expanding the diameter of the opening end of the tube from the inside. The outer peripheral portion of the first peripheral wall end portion has a flange that axially faces the peripheral wall end portion of the tubular body. The outer peripheral surface of the bulging portion of the sleeve may receive a pressing force from the inner peripheral surface of the nut.

The sleeve according to the invention comprises a flange on the outer periphery of the first peripheral wall end. When the tube flexes, this flange contacts the peripheral wall end of the fitting body. Therefore, regardless of the bending of the tube, the axis of the sleeve does not excessively tilt from the axial direction of the joint body. Thus, the joint using this sleeve can be further miniaturized in the axial direction of the sleeve while maintaining high sealing performance.

(A) is a perspective view showing an appearance of a joint according to an embodiment of the present invention, and (b) is an exploded view of the joint. 1A is a vertical cross-sectional view taken along the line II-II shown in FIG. 1A, and FIG. 1B is an enlarged view of a portion surrounded by a broken line shown in FIG. (A) is a longitudinal sectional view showing a first modification of the seal structure according to the embodiment of the present invention. (B) is a longitudinal sectional view showing a second modified example of the seal structure.

Embodiments of the present invention will be described below with reference to the drawings.

1A is a perspective view showing the outer appearance of a joint according to an embodiment of the present invention, and FIG. 1B is an exploded view of the joint 100. The joint 100 is installed, for example, at the discharge port of the pump 200, and the tube 300 is connected to the discharge port. The tube 300 is a white or translucent tube made of a fluororesin such as polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA). The fitting 100 includes a tubular body 110, a sleeve 120, and a nut 130.

The cylindrical main body 110 is a cylindrical member made of fluororesin such as PTFE or PFA, and is formed as a male screw (a cylindrical structure having a screw formed on the outer peripheral surface) whose axial length is shorter than that of the nut 130. ing. The tubular main body 110 is coaxially fixed to the discharge port of the pump 200. An annular groove 111 is formed along the periphery of the end of the peripheral wall of the cylindrical body 110.

The sleeve 120 is a cylindrical member made of fluororesin such as PTFE or PFA, and is arranged coaxially with the cylindrical main body 110. The sleeve 120 has the same inner diameter as the tubular body 110. The first peripheral wall end 121 of the sleeve 120 faces the peripheral wall end of the tubular body 110, and the second peripheral wall end 122 is press-fitted into the open end of the tube 300. The first peripheral wall end 121 includes an annular protrusion 123 and a flange 124, and the second peripheral wall end 122 includes a bulge 125. The annular protrusion 123 projects from the entire circumference of the first peripheral wall end 121 in the axial direction of the sleeve 120 (negative direction of the Y-axis in the figure) and is press-fitted into the annular groove 111 of the tubular body 110. The flange 124 radially projects from the base end of the annular protrusion 123 of the first peripheral wall end 121. That is, the flange 124 has a larger outer diameter than the annular protrusion 123. The outer diameter of the bulging portion 125 is gradually increased or decreased according to the position of the sleeve 120 in the axial direction (Y-axis direction), and the diameter of the bulging portion 125 is maximized at the central portion of the second peripheral wall end portion 122 in the axial direction ( Peak) is included. Since the outer diameter of this peak is larger than the inner diameter of the tube 300, the bulging portion 125 is press-fitted into the opening end of the tube 300 to expand the opening end from the inside. The elastic force of the tube 300 against this expansion acts so that the open end of the tube 300 embraces the bulging portion 125 of the sleeve 120, so that the open end is firmly fixed to the second peripheral wall end 122 of the sleeve 120. To be done.

The nut 130 is a cylindrical member made of a fluororesin such as PTFE, PFA, or polyvinylidene fluoride (PVDF), and is arranged coaxially with the cylindrical main body 110. The outer diameter of the nut 130 is larger than the outer diameter of both the tubular body 110 and the sleeve 120. One of the peripheral wall ends of the nut 130, which is closer to the tubular body 110, includes a female screw (a cylindrical structure having a screw formed on the inner peripheral surface) that meshes with the male screw of the tubular body 110. When the male screw of the tubular body 110 is screwed into this female screw, the tubular body 110 and the sleeve 120 are housed inside the nut 130. The tube 300 is inserted into the open end of the nut 130 located on the side opposite to the tubular body 110.

2A is a vertical cross-sectional view taken along a line II-II shown in FIG. 1A, and FIG. 2B is an enlarged view of a portion surrounded by a broken line shown in FIG. It is a figure. The inner diameter of the nut 130 narrows in three steps as it moves away from the tubular body 110 in the axial direction (the positive direction of the Y-axis). Accordingly, the nut 130 is divided into the first portion 131, the second portion 132, and the third portion 133. The first portion 131 is closest to the tubular body 110, the third portion 133 is farthest from the tubular body 110, and the second portion 132 is located between the first portion 131 and the third portion 133. Since the inner diameter D1 of the first portion 131 is equal to the outer diameter of the tubular main body 110, the male screw of the tubular main body 110 meshes with the female screw of the inner peripheral surface. The second portion 132 faces the second peripheral wall end portion 122 of the sleeve 120 with the tube 300 interposed therebetween. The inner diameter D2 of the second portion 132 is equal to or slightly smaller than the outer diameter of the bulging portion 125 of the sleeve 120 plus the thickness of the tube 300. Therefore, the inner peripheral surface of the second portion 132 contacts the outer peripheral surface of the tube 300. In particular, when the inner diameter D2 is smaller than the outer diameter of the bulging portion 125 of the sleeve 120 plus the thickness of the tube 300, the radial pressure P1 corresponding to the narrowness is applied from the inner peripheral surface of the second portion 132. It is added to the outer peripheral surface of the tube 300. The tube 300 is inserted inside the third portion 133. The inner diameter D3 of the third portion 133 is equal to or slightly larger than the outer diameter of the tube 300. As the bulging portion 125 of the sleeve 120 expands the diameter of the tube 300 inside the second portion 132 of the nut 130, the end portion 134 of the third portion 133 adjacent to the second portion 132 becomes the outer peripheral surface of the tube 300. Slightly bite into it. This prevents the tube 300 from coming off.
[Seal structure between body and sleeve]

The first peripheral wall end 121 of the sleeve 120 forms a seal structure with the peripheral wall end of the tubular body 110. In this seal structure, the annular protrusion 123 of the sleeve 120 is press-fitted into the annular groove 111 of the tubular body 110. Since the annular projection 123 has a slightly larger radial width than the annular groove 111, the annular projection 123 is press-fitted into the annular groove 111, so that the annular groove 111 is pressed from the outer peripheral surface and the inner peripheral surface of the annular projection 123, respectively. A radial pressure P2 is applied to the inner surface of the. As a result, the outer peripheral surface and the inner peripheral surface of the annular protrusion 123 are pressure-bonded to the inner peripheral surface and the outer peripheral surface of the annular groove 111 without a gap. In this seal structure, the peripheral wall end of the tubular body 110 further includes the tapered surface 112, and the first peripheral wall end 121 of the sleeve 120 includes the tapered surface 126. The tapered surface 112 of the cylindrical main body 110 is located on the inner diameter side of the annular groove 111, and the diameter thereof increases in the axial direction (Y (Axial direction). The tapered surface 126 of the sleeve 120 is located on the inner diameter side of the annular protrusion 123, and extends in the axial direction (Y-axis direction) so that the diameter increases toward the outer side (positive side of the Y-axis) along the axial direction of the sleeve 120. It is inclined to. The tapered surface 112 of the tubular body 110 and the tapered surface 126 of the sleeve 120 have the same inclination, and when the nut 130 is screwed into the tubular body 110, the whole is in contact. Further, the pressure P1 applied to the tube 300 by the second portion 132 of the nut 130 and the pressure P3 applied to the bulging portion 125 of the sleeve 120 by the tube 300 are transmitted as stress inside the sleeve 120. As a result, the pressure P4 is applied to the tapered surface 112 of the tubular body 110 from the tapered surface 126 of the sleeve 120, so that the tapered surfaces 112 and 126 are pressed against each other without a gap. In this way, the boundary between the tubular body 110 and the sleeve 120 is sealed.
[Role of sleeve flange]

The flange 124 of the sleeve 120 projects in the radial direction (Z-axis direction in FIG. 2) from the base end of the annular projection 123. One of the end faces of the flange 124, which is closer to the tubular body 110, is arranged at a predetermined distance from the tubular body 110, and the one, which is farther from the tubular body 110, is in contact with the peripheral wall end of the tube 300.

Flange 124 serves to keep sleeve 120 coaxial with tubular body 110 against deflection of tube 300, as described below. When the tube 300 bends, the tube 300 tilts with respect to the axial direction (Y-axis direction) of the tubular main body 110, for example, as indicated by a chain double-dashed line and an arrow in FIG. In response to this, the axis of the sleeve 120 is also tilted as shown in FIG. When this inclination reaches the allowable upper limit, the corner of the flange 124 comes into contact with the tubular main body 110, so that the inclination of the axis of the sleeve 120 exceeding the allowable upper limit is prevented. That is, the gap formed by the tubular main body 110 and the flange 124 is maintained at a distance such that the inclination of the flange 124 does not reach the allowable upper limit. Thus, the flange 124 can keep the sleeve 120 coaxial with the tubular body 110 within an acceptable range, regardless of the deflection of the tube 300.
[Advantages of Embodiment]

The sleeve 120 according to the above-described embodiments of the present invention includes a radially projecting flange 124. When the tube 300 bends, the flange 124 contacts the tubular body 110 of the fitting 100. As a result, the axis of the sleeve 120 does not excessively tilt with respect to the axial direction (Y-axis direction) of the tubular main body 110 regardless of the bending of the tube 300. That is, unlike the structure disclosed in Patent Document 1, for example, even if the tubular main body 110 is not provided with a portion for holding the peripheral wall end of the tube 300, the sleeve 120 can be kept coaxial with the tubular main body 110. it can. In this way, the tubular main body 110 can be shortened in the axial direction without affecting the sealing structure and sealing performance with the first peripheral wall end 121 of the sleeve 120. As a result, the joint 100 can be further downsized in the axial direction of the sleeve 120 while maintaining high sealing performance.
[Modification]

(1) The joint 100 according to the above-described embodiment of the present invention is installed at the discharge port of the pump 200. Alternatively, the joint 100 may be installed at the suction port of the pump 200. Further, it may be installed in a device other than the pump, for example, a valve, a suction port or a discharge port of a sensor. Furthermore, the joint 100 may be applied not only to the connection between the device and the tube but also to the connection between the tubes.

(2) The flange 124 according to the above-described embodiment of the present invention continuously and radially projects from the entire circumference of the first peripheral wall end 121 of the sleeve 120. In addition, the flanges may be arranged discretely or separately in the circumferential direction of the first peripheral wall end portion.

(3) As shown in FIG. 2, when the sleeve 120 is combined with the tubular body 110, the taper surface 112 of the tubular body 110 and the taper surface 126 of the sleeve 120 are inclined due to the pressure P4 and its reaction force. Are equal. On the other hand, when the sleeve 120 is separated from the tubular body 110, the tapered surface 112 of the tubular body 110 and the tapered surface 126 of the sleeve 120 may have the same inclination or different inclinations. When the sleeve 120 is combined with the tubular body 110, as described above, the pressure P4 is applied to the tapered surface 112 of the tubular body 110 from the tapered surface 126 of the sleeve 120, so that the tapered surfaces 112 and 126 have different inclinations. Even if they are attached, they should be crimped together without a gap.

(4) In the seal structure according to the above-described embodiment of the present invention, the tubular body 110 of the joint 100 includes the annular groove 111 at the peripheral wall end, and the sleeve 120 includes the annular protrusion 123 at the first peripheral wall end 121. Conversely, the tubular body may include an annular protrusion and the sleeve may include an annular groove.

FIG. 3A is a vertical cross-sectional view showing a first modified example of the seal structure. This figure is an enlarged view of the portion corresponding to the broken line portion shown in FIG. 2A in the seal structure. The tubular body 110 includes an annular protrusion 311 at the end of the peripheral wall. The annular protrusion 311 projects in the axial direction (the positive direction of the Y-axis) from the entire circumference of the tubular main body 110. The sleeve 120 includes an annular groove 321 along its circumference at the first peripheral wall end 121. The annular protrusion 311 is press fitted into the annular groove 321. Since the annular protrusion 311 has a slightly larger radial width than the annular groove 321, the annular protrusion 311 is press-fitted into the annular groove 321 so that the annular protrusion 311 has an outer peripheral surface and an inner peripheral surface, respectively. A radial pressure P5 is applied from the inner surface of 321. As a result, the outer peripheral surface and the inner peripheral surface of the annular protrusion 311 are pressed against the inner peripheral surface and the outer peripheral surface of the annular groove 321 without a gap.

In this seal structure, the peripheral wall end of the tubular body 110 includes the first tapered surface 312 and the second tapered surface 313, and the first peripheral wall end 121 of the sleeve 120 includes the first tapered surface 322 and the second tapered surface 323. Including and The first tapered surface 312 of the tubular main body 110 is located on the inner diameter side of the annular protrusion 311, and the axial direction is such that the diameter becomes narrower toward the outer side (the positive side of the Y axis) along the axial direction of the tubular main body 110. It is inclined with respect to (Y-axis direction). The second tapered surface 313 of the tubular main body 110 is located on the outer diameter side of the annular protrusion 311 and has a diameter that increases along the axial direction of the tubular main body 110 toward the outside (positive side of the Y axis). It is inclined with respect to the direction (Y-axis direction). The first tapered surface 322 of the sleeve 120 is located on the inner diameter side of the annular groove 321, and the first taper surface 322 is formed in the axial direction (Y-axis direction) so that the diameter becomes narrower toward the outer side (the positive side of the Y-axis) along the axial direction of the sleeve 120. ) Is inclined to. The second taper surface 323 of the sleeve 120 is located on the outer diameter side of the annular groove 321, and the diameter thereof increases in the axial direction (Y-axis) so that the diameter increases toward the outer side (the positive side of the Y-axis) along the axial direction of the sleeve 120. Direction). In the state where the sleeve 120 is combined with the tubular body 110, the first tapered surface 312 of the tubular body 110 and the first tapered surface 322 of the sleeve 120 have the same inclination, and the first tapered surface 312 and the second tapered surface 313 of the tubular body 110 have the same inclination. The inclination is equal to that of the second tapered surface 323 of the sleeve 120. That is, when the nut 130 is screwed into the tubular main body 110, the first tapered surfaces 312 and 322 are entirely in contact with each other, and the second tapered surfaces 313 and 323 are entirely in contact with each other. As described above, in the state where the sleeve 120 is separated from the tubular body 110, the first tapered surface 312 of the tubular body 110 and the first tapered surface 322 of the sleeve 120 have the same inclination or different inclinations. Alternatively, the second tapered surface 313 of the tubular body 110 and the second tapered surface 323 of the sleeve 120 may have the same inclination or different inclinations. Due to the pressure P1 given to the tube 300 by the second portion of the nut 130 and the pressure P3 given to the bulging portion 125 of the sleeve 120 by the tube 300, the first tapered surface 312 of the tubular main body 110 has a first tapered surface of the sleeve 120. The pressure P6 is applied from 322, and the pressure P7 is applied from the second tapered surface 323 of the sleeve 120 to the second tapered surface 313 of the tubular main body 110. Therefore, the first tapered surfaces 312 and 322 are pressure-bonded to each other without a gap, and the second tapered surfaces 313 and 323 are pressure-bonded to each other without a gap. In this way, the boundary between the tubular body 110 and the sleeve 120 is sealed.

(5) In the sleeve 120 according to the above-described embodiment of the present invention, the flange 124 is provided at a distance from the tubular main body 110. Accordingly, even if the nut 130 is excessively tightened on the tubular body 110 by retightening or the like, the flange 124 does not come into contact with the tubular body 110. In addition, it is not essential that the flange 124 is provided at a distance from the tubular body 110, and the flange 124 may be in contact with the tubular body 110. In addition, a seal structure using a tapered surface may be formed between the flange 124 and the tubular body 110.

FIG. 3B is a vertical sectional view showing a second modification of the seal structure. This figure is an enlarged view of the portion corresponding to the broken line portion shown in FIG. 2A in the seal structure. The cylindrical main body 110 includes an annular tapered groove 411 formed along the circumference on the outer diameter side of the annular groove 111, and the flange 124 of the sleeve 120 is provided on the end surface on the cylindrical main body 110 side on the entire circumference thereof. An annular tapered protrusion 421 protruding in the direction (negative direction of the Y-axis) is included. The taper groove 411 of the tubular main body 110 is inclined with respect to the axial direction (Y-axis direction) so that the diameter becomes narrower toward the outer side (the positive side of the Y-axis) along the axial direction of the tubular main body 110. There is. The taper protrusion 421 of the sleeve 120 is inclined with respect to the axial direction (Y-axis direction) so that the diameter becomes narrower toward the outer side (positive side of the Y-axis) along the axial direction of the sleeve 120. When the sleeve 120 is combined with the tubular body 110, the taper groove 411 of the tubular body 110 and the taper protrusion 421 of the sleeve 120 have the same inclination. (In the state where the sleeve 120 is separated from the tubular body 110, the taper groove 411 of the tubular body 110 and the tapered protrusion 421 of the sleeve 120 may have the same inclination or different inclinations.) The tubular body 110 When the nut 130 is screwed in, the taper protrusion 421 is pressed into the taper groove 411. Further, due to the pressure P1 applied to the tube 300 by the second portion of the nut 130 and the pressure P3 applied to the bulging portion 125 of the sleeve 120 by the tube 300, the pressure P8 is applied to the tapered groove 411 from the tapered protrusion 421. Therefore, the taper protrusion 421 is pressure-bonded to the taper groove 411 without a gap. In this way, the sealing property between the tubular body 110 and the sleeve 120 can be further improved.

(6) The resin material of the joint 100 according to the above embodiment of the present invention is not limited to fluororesin. In addition, various resins such as polyethylene, polypropylene, polycarbonate, polyamide, polyacetal, polyether ether ketone, polyphenylene sulfide, and polyimide can be used. These are appropriately selected depending on the field of use or application of the joint 100, the material of the tube 300, and the like.

(7) The joint 100 according to the above-described embodiment of the present invention includes a plurality of pipes used not only in the semiconductor, liquid crystal, or organic EL manufacturing apparatus but also in various plant pipes, medical/pharmaceutical pipes, and the like. It can also be used as a member for connecting devices and the like.

Reference Signs List 100 joint 110 tubular body of joint 111 annular groove of tubular body 112 tapered surface of tubular body 120 sleeve 121 first peripheral wall end portion of sleeve 122 second peripheral wall end portion of sleeve 123 annular protrusion of sleeve 124 sleeve flange 125 Bulging part of sleeve 126 Tapered surface of sleeve 130 Nut 131 First part of nut 132 Second part of nut 133 Third part of nut 134 End of third part of nut 200 Pump 300 Tube

Claims (6)

A cylindrical member for connecting a tube to a tubular body of a joint,
A first peripheral wall end facing the peripheral wall end of the tubular body;
A second peripheral wall end portion press-fitted into the open end portion of the tube,
The first peripheral wall end is
An annular protrusion that is press-fitted into an annular groove that the peripheral wall end portion of the tubular body includes, or an annular protrusion that axially protrudes an annular protrusion that the peripheral wall end portion of the tubular body includes is annularly press-fitted,
The second peripheral wall end is
It has a bulge for expanding the diameter of the opening end of the tube from the inside,
The outer peripheral portion of the first peripheral wall end portion is
A sleeve having a flange axially opposed to an end portion of the peripheral wall of the tubular body. The sleeve according to claim 1, wherein the flange is axially spaced from an end portion of a peripheral wall of the tubular body. The sleeve according to claim 1, wherein the flange is in contact with an end portion of a peripheral wall of the tubular body. The sleeve according to claim 3, wherein a contact portion of the flange with the end portion of the peripheral wall of the tubular main body includes an inclined surface with respect to the axial direction. A fitting to which a tube is connected,
At the peripheral wall end, a tubular body including a male screw extending in the axial direction,
A sleeve for connecting the tube to the peripheral wall end of the tubular body,
From one side, the tube is inserted inward, and from the other side, a nut into which a male screw of a peripheral wall end of the tubular body is screwed in
The sleeve is
A first peripheral wall end facing the peripheral wall end of the tubular body;
A second peripheral wall end portion press-fitted into the open end portion of the tube,
The first peripheral wall end is
An annular protrusion that is press-fitted into an annular groove that the peripheral wall end portion of the tubular body includes, or an annular protrusion that axially protrudes an annular protrusion that the peripheral wall end portion of the tubular body includes is annularly press-fitted,
The second peripheral wall end is
It has a bulge for expanding the diameter of the opening end of the tube from the inside,
The outer peripheral portion of the first peripheral wall end portion is
A joint having a flange axially opposed to an end of the peripheral wall of the tubular body. The joint according to claim 5, wherein the outer peripheral surface of the bulging portion of the sleeve receives a pressing force from the inner peripheral surface of the nut.